I am aware that gear pumps, separate from the extrusion die of an extrusion apparatus, have been heretofore used to supply coating to a coating nozzle.
It has also been proposed, as in U.S. Pat. No. 3,162,886 to Wise of Dec. 29, 1964, to provide a pair of outlet nozzles leading from a hopper containing mortar, each nozzle having an elongated helical feed auger therewithin for delivering mortar to each opposite side of cement block structures.
In U.S. Pat. No. 3,333,567 to Rich, et al, of Aug. 1, 1967 a butter extruder is disclosed in which a thin sheet of butter is extruded from a nozzle with the assistance of a single, elongated gear pump, full length of the nozzle and a manifold housing full of packed butter under pressure.
However, as far as I am aware the prior art has not disclosed an elongated, narrow, extrusion slot nozzle for extruding a thin, layer of uniform thickness onto a moving web of material, the nozzle having a built-in gear pump formed in a rectilinearly, axially, aligned, set of separate intermeshed pairs of gears, spaced apart preferably by carbon bearings, all parts removable for cleaning and channeled for heating or cooling.